Vitamins and minerals like iron, calcium, vitamin D are all affected
12:12, 06 Mar 2025
Elderly woman pouring vitamin pills on hand (Photo by Universal Images Group via Getty Images)
Coffee drinkers have been warned(Image: UIG via Getty Images)
Experts have warned that your morning cuppa could be making your vitamins less effective. The choice of drink can impact not only your bones but also your overall health, even if you're taking a variety of vitamins. Research into the influence of energy and normal caffeine consumption and the effects of low doses of caffeine on human performance and mood has revealed that while moderate caffeine intake can boost mental and physical performance, overdoing it can lead to negative side effects such as anxiety, insomnia, high blood pressure, and fatigue.
A study highlighted a link between vitamin and mineral absorption levels. Health experts from Livestrong explain that these essential nutrients need to be absorbed into the bloodstream to work effectively.
But your pre-work coffee could be disrupting this process. For example, when it comes to Vitamin D, researchers from Creighton University and the University of Miami found that caffeine can hinder the absorption of this vitamin.
Vitamin D and caffeine
Close up of human hands. He is taking pill
Vitamin D plays a vital role in our health(Image: Getty)
Their study, published in the Journal of Steroid Biochemistry and Molecular Biology, shows that higher caffeine levels result in greater interference with vitamin D absorption. Experts think this happens because caffeine reduces the expression of vitamin D receptors on osteoblasts, the cells that produce bone.
Iron and caffeine
Iron and caffeine are also linked, reports the Mirror. Iron supplements could be less effective if taken with coffee, as research indicates. One study highlighted: "A cup of coffee reduced iron absorption from a hamburger meal by 39% as compared to a 64% decrease with tea, which is known to be a potent inhibitor of iron absorption."
The impact of coffee on iron absorption was further detailed: "When a cup of drip coffee or instant coffee was ingested with a meal composed of semipurified ingredients, absorption was reduced from 5.88% to 1.64 and 0.97%, respectively, and when the strength of the instant coffee was doubled, percentage iron absorption fell to 0.53%."
Summarising the findings, the study stated: "These studies demonstrate that coffee inhibits iron absorption in a concentration-dependent fashion."
Calcium and caffeine
yogurt
If you have calcium in your breakfast, try delaying your tablets(Image: Getty)
Coffee consumption has been shown to slightly hinder calcium absorption and promote increased calcium excretion through urine, according to a study in Osteoporosis International.
This diuretic effect of coffee can have implications for bone health. Additional research with 205 postmenopausal women, published in the American Journal of Clinical Nutrition, suggests that those with low milk or calcium intake who consume two or more cups of coffee daily might face accelerated bone loss.
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A study from Norway, involving nearly 20,000 women, indicated that drinking nine or more cups of coffee per day may increase the risk of bone fractures. An article from the American Journal of Clinical Nutrition further suggests that older women who have cola every day could have a lower bone mineral density than those who drink it less frequently.
Can I still drink coffee and take vitamins and minerals?
Yes. The same same study showing implications for burgers and absorption investigated coffee's impact on iron absorption, noting specifically: "No decrease in iron absorption occurred when coffee was consumed 1 h before a meal, but the same degree of inhibition as with simultaneous ingestion was seen when coffee was taken 1 h later."
For those taking vitamins to combat fatigue, boost bone health, or address other conditions, consider decreasing caffeine consumption, especially if you're prone to having it in high quantities. To err on the side of caution, consulting a GP and getting proper testing is advisable as this will help to see what you need and the exact dosage required - as well as any potential interference with their efficacy.